Auxiliary air supply device for internal combustion engines



Feb. 25, 1941. 3 2,232,784

AUXILIARY AIR SUPPLY DEVICE FOR INTERNAL COMBUSTION ENQINES Filed Dec.2, 1938 \wcnccll m as 39 Patented Feb. 25, 1941 UNITED STATES PATENTOFFICE AUXILIARY AIR SUPPLY DEVICE FOR INTERNAL COMBUSTION ENGINES NancyHifner, Lexington, Ky.

Application December 2, 1938, Serial No. 243,673

My invention relates to 1 Claim.

a device for supplying auxiliary air into the carbureter system forinternal combustion engines for automotive vehicles and moreparticularly to the automatic control means for varying the amount ofair supplied at various throttle openings in the intake system.

It is desirable to furnish a rich mixture to the engine or starting andat low speeds of travel of the motor drive n vehicle and then to varythe mixture as the speed of travel increases.

An object of the present invention is to provide a control valve whichaccurately meters the amount of auxiliary air admitted to the air andfuel mixture with actuating means for varying the amount of air suppliedhaving connections with the throttle or throttle control means so as tobe variably operated therewith.

Another object of the in with the metering of the vention in conjunctionauxiliary air supplied to the fuel mixture is to provide adjusting meansin the connection of the valve with the throttle operating means wherebythe valve can be set to open at any given speed and the opening isthereafter variably increased as the speed is increased.

A further object of the invention is to provide such auxiliary aircontrol of attachments which are and inexpensive to manuf apparatus inthe form simple in construction acture and which may be easily andquickly applied to automotive vehicle engines.

Further objects and details of the invention will appear as described inconnection with a highly satisfactory embodiment thereof which isillustrated in the accompanying drawing and hereinafter set forth andclaimed.

Referring to the drawing in which like characters of reference designatesimilar parts throughout the several views:

Figure 1 is a side elevation illustrating a downdraft air intake andcarbureter for an internal combustion engine of a n automotive vehiclesame and Figure 5 is a cross sectional view taken on line 5-5 of Figure4.

.In general Figure 1 illu strates the manner in intake manifold (notshown).

which auxiliary air control apparatus A in accordance with my inventionmay be connected with a conventional downdraft intakeof an internalcombustion engine. This intake as shown comprises an air filter B belowwhich it is con- 5 nected to a carbureter C which in turn is connectedwith the inlet passage D tothe engine These parts of the enginedowndraft intake are conventional having the usual air and fuel passagestherethrough and the carbureter is provided with the usual controlmembers, reference to some of which will be made.

The carbureter is shown as having a forwardly extending fuel floatchamber It, choke means, generally designated H which is operatedthermostatically or in any other approved manner and several othercontrols for illustrative purposes only. In applying my invention tosuch a downdraft intake it will be noted that the carbureter has,adjacent to its lower portion, a throttle or accelerator butterfly typeof valve 12 illustrated in dotted lines in its closed position and onthe exterior of the passage an operating lever arm I3 is connected tothe shaft of this valve for rotating it which in turn is connected withthe accelerator rod M which when moved in the direction of the arrowturns the lever in a counter clockwise direction to open the valve (2.This lever has a downwardly ex- 130 tending arm i5 which controls theauxiliary air intake. Other carbureter elements and their controls arenot disclosed as they are not neces sarily connected with the auxiliaryair intake apparatus in accordance with the present in- '85 vention anda complete understanding thereof. In order to supply auxiliary air tothe air and fuel mixture supplied to the engine I provide an adapter l6which is bolted in the intake between the carbureter C and the inletpassage D. This 40 adapter is relativelyjiat and as shown in the detailsectional view, Figure 2, it has a passageway which is preferablyaslarge as and corresponding in shape with the intake passageway at thispoint and holes [8 provided therein provide passages through which thecarbureter securing bolts may extend in securing the members in place.The adapter is provided with a lateral inlet duct IS .with which acontrol valve 29 is connectedor bymeans of a conducting pipe 2| andfittings22 in order to place the valve in any desirable position withrespect .to the carbureter vC andits controls as illustrated by way .ofexamplein Figure 1.

Asillustratedin-detail in Figures '3, 4 and.5 &5

valve 20 consists of a hollow body member which is generally designatedby the same reference numeral 20. This body member has extending inwardfrom one end a large bore in the major portion thereof providing a valvechamber 23 having a substantially flat inner end 24 and extendingtherefrom is a reduced cylindrical bore 25 providing an air passagewaythrough the other end of the body. This end of the body is preferablysmaller in its exterior diameter threaded as shown at 26 for connectionwith adapter 16 or conductor leading thereto and in an intermediateposition, around the flat end portion 24 of the chamber 23 and extendingin a forward direction thereof is an enlarged collar 21, knurled tofacilitate in making connections and also provided with a plurality ofair passages 28 extending radially into chamber 23 slightly beyond thefiat inner end 24. There are preferably four passages 28 as best shownin Figure and these passages have a total cross-sectional area somewhatin excess of the cross-sectional area of passageway 25 whereby the airwill be free to flow through these passages so as to insure sufficientair to be delivered through passage 25 in accordance with the operationof the valve control means in chamber 23.

The portion of body 20 surrounding valve chamber 23 is exterlorlythreaded at 29 throughout the greater portion of its length forreceiving a cylindrical cap nut 30 and a locking nut 3| each havinginternal threads which cooperate with threads 29 on body 20. Cap nut 30provides an adjusting member for the control valve and is of a lengthsuch that it may substantially cover the threaded portion surroundingchamber 23 or may be adjusted outwardly thereon, increasing the lengthof chamber 23 from the inner flat end 24 to the end 32 of cap nut 30which end is provided with a concentric bore 33.

Housed within chamber 23 between the inner end 24 thereof and end 32 ofcap nut 30 i the valve mechanism comprising a longitudinal operatingplunger 34 extending concentrically therein with its outer end extendingthrough bore 33 of cap nut 30. This plunger is provided with a collar orstop member 35 which is engageable with the end 32 of cap nut 33 as alimit when the plunger is drawn outwardly and adjacent to the inner endof plunger 34 is a piston member 36 which slides along the cylindricalwalls of chamber 23 with a Loose fit permitting a limited flow of airtherebetween. Extending inwardly from plunger 34 and piston 36 is a pinmember 31 having a diameter, at the surface of the piston 36, slightlyless than that of bore 25, and of gradually decreasing diameter as itextends away from the piston so as to provide a relatively long taperedmetering pin. These elements, stop member 35, piston 36 and pin 31 maybe made as a part of plunger 34 or joined therewith in any desiredmanner. Surrounding plunger 34 and stop member 35 is a compressionspring 38 which has its inner and outer ends seated between the outerend surface of piston 36 and the inner surface of the cap nut end 32 andby adjustment of cap nut 30 on threads 29 the force of the spring actingon the plunger and the outer limit for stop member 35 may be varied. Itwill be noted that the inner end surface of piston 36 is relatively flatand in normal inoperative position of the engine or at low throttleopenings spring 38 acts with sufficient force to seat this end surfaceof piston 36 into cooperation with the fiat'end wall 24 sets to substa tcut oif any flow of air to and through passage 25. In Figure 4, however,the plunger and valve are shown in an outer position so that the valveis at least partially open.

The external end of plunger 34 is preferably apertured at 39 to providesuitable means for connecting a valve operating spring 40 therewith, andas shown, in Figure l the other end of this operating spring isconnected with arm l5 so as to be drawn thereby when the accelerator rodI4 is actuated to open valve l2. The tension of Spring 40 is sufficientto overcome spring 38 when the accelerator rod I4 i operated to openvalve 12 and the coaction of the two springs is controllable by varyingthe adjustment of cap nut 30 inwardly or outwardly along threads 29 onbody 20., It will thus be seen that the point of opening of the valvemay be adjusted with respect to the engine throttle opening and whiledriving the vehicle its adjustment is such as to effect the opening atand above a predetermined speed. By this adjustment means alsovariations in the increase of the amount of auxiliary air supplied asthe throttle is opened greater amounts may be had, the tapered pin 31 inits cooperation with cylindrical passage 25 affords an accurate meansfor metering the amount of air supplied, whereby the amount of auxiliaryair supplied for all throttle openings and corresponding speeds of theengine may be accurately determined.

When the engine is operated the valve which is in closed position whenthe engine throttle I2 is closed, is drawn in an opening direction afterthe valve l2 has been opened a predetermined amount and then isincreasingly opened as the throttle opening is increased, as referred toabove. It will be noted from a closed position, the flat surface ofpiston 36 in engagement with surface 24, the piston first unseats andpermits a small amount of air to flow from openings 28 over theperiphery of the piston at its inner edge and thence between said fiatend walls and into passage 25 around tapered pin 31. As the piston movesoutwardly it uncovers air passages 28 to a greater and greater extentuntil they are entirely open, thus effecting a metering of the air flowthrough these openings for an initial portion of the outward openingmovement of the plunger and piston. At the same time, as the piston isbeing moved outwardly, however, tapered pin 31 is also moved outwardlyfrom passage 25 increasing the passage opening and definitely meteringor controlling the amount of auxiliary air supplied in accordance withthe position of the piston in chamber 23 and pin 31 in passageway 25.Pin 31 is also operative to continuously increase the amount afterpiston 36 has passed passages 28 until the end of pin 31 is entirelywithdrawn from passage. 25 or stop member 35 engages end 32 of cap nut30, depending upon the adjustment thereof. Cap nut 30 when positionedoutwardly on body 20 permits a greater flow of auxiliary air through thevalve than when in an inner position and by positioning it inward theamount may be materially limited. The correct amount of air supplied isthus controlled and while the selection of springs 38 and 40 withrespect to each other has a decided influence upon the operation of thevalve it is not critical since variations of the springs may becompensated for by adjustment of the cap nut 30. From the foregoing,numerous advantages of my auxiliary air control apparatus will bereadily apparent to those skilled in the art.

Having set forth a highly satisfactory embodiment of my invention I donot Wish to limit myself to any of the specific construction or modes ofoperation described above in this specification for purposes of givingan example or illustration of employment of the invention, for it willbe obvious that wide departure from the above may be made withoutdeparting from the spirit and scope of my invention, which is as setforth in the following claim.

I claim:

Auxiliary air supply apparatu for internal combustion engines includinga valve member having a cylindrical passageway therethrough, a plungerhaving a tapered pin extending into said passageway, said valve memberhaving a housing beyond said cylindrical passageway through whichhousing the plunger extends, said housing having an inwardly andoutwardly adjustable uter end member, locking mean for said adjustableouter end member, a spring within said housing engaging the outer endmember thereof and urging the tapered pin into the cylindricalpassageway of the valve member, a piston element on said plunger beyondwhich the tapered pin extends, said piston to be engaged on one side bysaid spring and its other side adapted to engage the valve member at theend of the passageway to close the same when the plunger is in itsinnermost position, said housing having a plurality of radial aperturesextending therethrough, said apertures adapted to be uncovered by thepiston as the piston moves outwardly in the housing, the tapered pinmovable with the piston to variably control the cylindrical passagewayas the piston moves to variably uncover the apertures, a stop collar onthe plunger outward from the piston adjacent to and engageable with theouter end member of the housing to limit the extent of outward movementof the plunger and tapered from the cylindrical passageway of the valvemember, and a spring for connecting the outer end of the plunger with avalve operator, said springs cooperating in the operation of the taperedpin on the plunger and adjustable with respect to each other by inwardor outward adjustment of the outer end member of the housing.

NANCY HIFNER.

